The first sign that he is ready to commit is that he sticks to his word. If he says he will do something, no matter how small, he won't forget about it, and will do it for you. If he is ready to commit to the little things, and does what he says he will do, then this is a huge sign that he is ready to commit. But do not be alarmed if he forgets things every once in a while, for example, to put the toilet seat down. As long as they are not critical (OK, to us girls the example I gave IS critical!), he may still be ready for commitment.
Pay attention to the way he touches you. Is he only grabbing you in places where horny teenagers would? Or is he stroking your hair, massaging your shoulders, and kissing you where he knows you like it best?
A man who is ready to commit will not only pay attention to his needs, but will put yours first.
He includes you in his life, even when he has had a bad day. A man who is ready to commit will let you into his life, and is not afraid to share both the good and the bad. So if he's had a horrible day at work, or if he had a fight with one of his friends or family, he will tell you.
He never mentions his exes or previous affairs. A man who is over his previous relationships and is ready to move on, will very rarely mention his ex. And honestly, you shouldn't ask. The less you know about that, the better.
He introduces you to his friends/ family. If he sees that there is a potential for commitment, he will introduce you to his friends and family, and will listen to what they have to say about you. If you are a hit, then more power to you!